Rule 1: For every calculated
normal stress there is a corresponding induced shear stress; the value of the shear
stress is equal to half that of the normal stress.

Rule 2: For every calculated shear stress
there is a corresponding induced normal stress; the value of the normal stress is equal to
that of the shear stress. The tables of combined stress formulas, below, include equations
for calculating both maximum nominal tensile or compressive stresses, and maximum
nominal shear stresses.